The macrocyclic lactone is an important structural motif in the chemistry of perfumery ingredients. In particular, macrocyclic lactones are valued for the desirable musk odour they can deliver to all manner of consumer products in both fine and technical perfumery.
The odour of musk is perhaps the most universally appreciated olfactive signal in perfumery. Synthetic musks can be divided into three major classes: aromatic nitro musks, polycyclic musks and macrocyclic musks. However, the detection of the nitro- and polycyclic chemical groups in human and environmental samples initiated a public debate on the use of these compounds; and some research suggested that these musk compounds do not break down in the environment and can accumulate in human bodies. As such, macrocyclic musks have increased in importance for perfumers in recent years.
Common macrocyclic musks include AMBRETTOUDE™ including 9-ambrettolide and 7-ambrettolide), NIRVANOUDE™, HABANOLIDE™ COSMONE™, MUSCENONE VELVIONE™, CIVETONE™ and GLOBANONE™
7-ambrettolide naturally occurs in musk ambrette seed oil (M. Kerschbaum, Chem Ber. 1927, 60B, 902) and is a valuable perfume base because of its desirable odour. 9-ambrettolide is likewise a much appreciated perfumery ingredient; it is currently synthesized industrially from aleuritic acid, which in turn is obtained from natural sources.
The availability and quality of naturally-occurring starting materials are, of course, dependent on climatic conditions, as well as socio-economic factors. Furthermore, since starting materials may be extracted from natural sources, sometimes with modest yields, they are available at prices that will, in all likelihood, increasingly render their use uneconomical on an industrial scale. Accordingly, if commercial industrial supplies of macrocyclic musks, such as AMBRETTOLIDE™, are to continue to be available at a reasonable cost, there is a need for more cost-effective industrially-scalable processes for their production, isolation and purification.